Air Conditioning: Operation: Notes

WARNING: This page is about a different car, the 2018 Land Rover Discovery and 2017 Land Rover Discovery. However, it is still accessible from the selected car via links, so may be relevant.

The Air Conditioning (A/C) compressor circulates the refrigerant around the system by compressing low pressure, low temperature vapor from the evaporator. The resultant high pressure, high temperature vapor is discharged to the condenser. In the condenser the vapor converts to a liquid, which then passes through the receiver drier and out of the condenser to the thermostatic expansion valve. As it passes through the thermostatic expansion valve, the liquid refrigerant changes to a fine, low pressure, spray, which is directed into the evaporator. In the evaporator the refrigerant changes back to a low pressure, low temperature vapor, as it absorbs heat from the air in the passenger compartment. The refrigerant returns to the A/C compressor to begin the cycle again.

Operation of the air conditioning system is controlled by the Automatic Temperature Control Module (ATCM). The ATCM adjusts the electronic control valve in the A/C compressor to match the refrigerant flow around the system to the thermal load of the evaporator. By matching refrigerant flow to the thermal load of the evaporator, the ATCM maintains the required temperature in the passenger compartment while maximizing fuel economy.